A B727 crew responded to a TCASII RA while on approach to pdx.

Attributes
ACN	520053
Time
Date	200107
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : pdx.airport
State Reference	OR
Altitude	msl single value : 1200
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	tower : pdx.tower
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : captain
Qualification	pilot : atp
Experience	flight time last 90 days : 30 flight time total : 11000 flight time type : 600
ASRS Report	520053
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : nmac other anomaly other
Independent Detector	aircraft equipment : tcas other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued advisory flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew other
Miss Distance	vertical : 300
Supplementary
Problem Areas	Flight Crew Human Performance Weather Environmental Factor ATC Human Performance Airspace Structure
Primary Problem	Flight Crew Human Performance

Narrative:

On ILS approach runway 28R, received a warning from tower of a pop-up target that they were not talking to at our 11 O'clock position. Received a TCASII RA approximately the same time. Initiated TCASII maneuver. Missed impending traffic by 300 ft. Filed a near miss report.

Original NASA ASRS Text

Title: A B727 CREW RESPONDED TO A TCASII RA WHILE ON APCH TO PDX.

Narrative: ON ILS APCH RWY 28R, RECEIVED A WARNING FROM TWR OF A POP-UP TARGET THAT THEY WERE NOT TALKING TO AT OUR 11 O'CLOCK POS. RECEIVED A TCASII RA APPROX THE SAME TIME. INITIATED TCASII MANEUVER. MISSED IMPENDING TFC BY 300 FT. FILED A NEAR MISS RPT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.